JP2910636B2 - How to replace a cutter bit and how to attach the cutter bit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for replacing a cutter bit and a structure for mounting the cutter bit. More particularly, the present invention relates to a method for replacing a cutter bit attached to a cutter face of a shield machine by a cutting operation. The present invention relates to a method for replacing a cutter bit for replacement and a mounting structure for a cutter bit mounted on a cutter face of a shield machine.

[0002]

2. Description of the Related Art Particularly in the field of urban civil engineering, a tunnel construction method using a shield machine is known as a method for excavating and forming a tunnel in the ground where groundwater is present or in a relatively soft ground. In this tunnel construction method using a shield excavator, while excavating a face with a shield excavator, a lining body covering the inner wall surface of the tunnel called a segment is sequentially assembled behind the excavation surface, and the inner wall surface of the tunnel is formed by such lining body. While protecting, the tunnel will be excavated and formed while obtaining the propulsion reaction force from this lining body.

[0003] In the tunneling method using this shield excavator, for example, a cutter disk or a cutter face provided at a tip portion of the shield excavator is used.
The cutter face is rotated while being pressed against the face of the tunnel, and the ground on the face is cut by a number of cutter bits attached to the cutter face. Excavation of the tunnel is performed while removing the water backward through a mud pipe or a screw conveyor.

Here, a large number of cutter bits attached to the cutter face are used as a tooth bit, an outer peripheral bit, a ring bit, a disk roller bit, and the like. A carbide chip made of tungsten carbide or the like is attached by silver brazing or the like, and the shank around the carbide chip is subjected to a hard fishing treatment or the like for preventing abrasion. And these cutter bits
These are firmly attached and fixed to cutter faces of various shapes such as a face plate type, a spoke type, and a dome type, respectively, by means of attachment such as pin attachment, bolt attachment, and welding attachment.

On the other hand, the tunnel construction method using a shield excavator has recently been aimed at increasing the depth and length of the tunnel. In order to cope with such long-distance construction, a cutting function of a cutter bit attached to a cutter face is required. Holding for a long time has become an indispensable matter. For this reason, conventionally, the cutting function of the cutter face is maintained by replacing the cutter bit, which has been worn or damaged due to long-term use and having a reduced cutting function, as appropriate, and restarting excavation work with a new cutter bit. The method was adopted.

[0006]

According to the conventional method of replacing a cutter bit, the so-called hermetic shield excavator having the face plate type, the spoke type, or the dome type cutter face,
During the excavation work in each section, it is difficult for the worker to directly enter the front of the cutter face.To replace such cutter bits, a special auxiliary method such as ground improvement is required separately. It is necessary to construct. Further, a method is also adopted in which a shaft for replacing a cutter bit is provided on the extension of the tunnel, and the front surface of the shield machine is reached in the shaft to perform the work of replacing the cutter bit.

However, in the conventional method of replacing the cutter bit, especially when the depth of the tunnel is deep, the above-described special auxiliary method and the installation work of the shaft require a lot of construction time and construction cost, so that economical construction is required. Cannot be performed. In addition, in particular, when the replacement work is performed underground while performing a special auxiliary construction method such as ground improvement, there is a problem that the replacement work may be forced in an unfavorable working environment.

Therefore, the present invention has been made in view of such conventional problems, and does not require any special auxiliary construction method or ancillary work such as a vertical shaft installation work. An object of the present invention is to provide a method of replacing a cutter bit, which can easily recover a cutting function of a cutter bit whose function has been impaired and enable long-distance tunnel excavation work by a shield machine. .

Further, the present invention can easily recover the cutting function of a cutter bit whose function has been impaired due to wear or damage, without requiring any special auxiliary method or additional work such as installation work of a shaft. It is an object of the present invention to provide a cutter bit mounting structure having a configuration capable of performing such operations.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and the gist of the invention is that when a cutter bit attached to a cutter face of a shield machine is worn by a cutting operation, the above-mentioned object is obtained. A replacement method for replacing a cutter bit, wherein a plurality of cutting tips are attached to a shank serving as a base material of the cutter bit, and the shank is urged to rotate about a central portion thereof. In a state in which the shank can be locked and fixed at each position where the plurality of cutting tips project from the front face of the cutter face, the cutter bit is attached to the cutter face, and the cutting tip is attached from the front face. At each protruding position, if the cutter bit is considerably worn, The cutting tip contributing to the cutting operation is released by unlocking and fixing the shank at the position where the next cutting tip protrudes from the front face of the cutter face while rotating the shank by the urging force. And a method for replacing a cutter bit, characterized in that the cutter bit is used for replacement.

In the above description, the condition in which the cutter bit is worn to a considerable degree means that the cutter bit is automatically released by, for example, the action of an urging force of an elastic body or the like. It refers to a state in which the bit is worn, and is appropriately designed in consideration of the strength of the material constituting the cutting tip or the shank, the mounting positions of the locking and fixing means and the releasing means, and the like.

The worn condition in the above description is as follows.
This is to be considered including the state where the shank and the cutting tip are damaged or broken.

In the method of replacing a cutter bit according to the present invention, a pair of the cutting tips is provided at both ends of the shank, and the shank is rotated by 180 ° by the urging force to fix the cutting tips. Can be used.

On the other hand, another gist of the present invention is a mounting structure of a cutter bit to be mounted on a cutter face of a shield machine, wherein a cutting bit having a pair of cutting tips provided at both ends of a shank serving as a base material is provided. A rotating shaft that penetrates the central portion of the shank and rotatably supports the cutter bit; a locking groove provided on the outer peripheral surface of the rotating shaft on the surface side of the cutter face; On the inner peripheral surface of the through hole in the central portion of the shank, a pair of locking piece receiving grooves provided to face each other in a direction intersecting the surface of the cutter face, and elasticity inside each of the locking piece receiving grooves. A locking piece having a height exceeding a depth of the locking groove, which is accommodated in a state urged toward the center of the rotation shaft by a member, and at least one of the locking pieces Inside the accommodating groove, the tip portion is located at the end of the shank by projecting and extending from the locking piece through the elastic member toward the outside of the rotating shaft via an elastic member. A projecting piece, and biasing means interposed between the shank and the rotating shaft or the cutter face for biasing the shank to rotate around the rotating axis, comprising the projecting piece. The locking piece and the locking groove are engaged and fixed in a state in which one locking piece receiving groove and the locking piece are positioned on the surface side of the cutter face, and one of the cuttings protruding and fixed from the surface of the cutter face is fixed. The cutting face is cut by the tip, and at the stage when the tip of the cutter bit is worn by a predetermined amount, the projecting piece is projected from the end face of the shank by the urging force of the elastic member so that the locking is performed. And to release the engagement between the locking groove, the cutter bit by the urging means 18
After rotating by 0 °, the engagement piece housed in the other opposite engagement piece housing groove is engaged and fixed to the engagement groove by the urging force of the elastic member, so that the worn end portion is formed. A cutting bit attached to an end opposite to the above is fixed so as to protrude from the surface of the cutter face, and a cutting operation is performed by the cutting tip.

In the above description, the stage where the tip of the cutter bit, from which the projecting piece projects, is worn by a predetermined amount means that the shank and the cutting tip are worn, and the tip of the locking piece receiving groove is worn. Opening or just before opening on the end face of the cutter bit, the biasing force applied to the protruding piece, the thickness between the tip of the locking piece receiving groove and the tip face of the cutter bit, or It is appropriately designed in consideration of the strength of the material constituting the shank and the like.

[0016]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The shield machine 20 according to this embodiment
As shown as a front view in FIG. 1, for example, a muddy shield excavator provided with a face plate type cutter face 1, and according to such a muddy shield excavator 20, a flat cutter face 1 is provided. The cutter bit 4 planted in large numbers on the surface of the
The cutting work is carried out while rotating the cutting face, and the cut soil is taken into the compartment provided behind the cutter face 1 through the slit opening 3 formed in the surface of the cutter face 1 and taken in. Earth and sand,
The excavation work is performed while mixing with muddy water fed into the compartment from behind the excavator 20 through the mud pipe and discharging the muddy water to the rear of the shield excavator 20 through the mud drainage pipe. .

According to the muddy shield machine 20, a lining body called a segment that covers the inner wall surface of the tunnel after excavation is assembled behind the shield machine 20 to collapse the surrounding ground. While performing tunnel excavation work while obtaining the propulsion reaction force of the shield machine 20 from the assembled segments.

The shield excavator 20 of this embodiment
According to each cutter bit 4 as a teeth bit
Are attached to the cutter face 1 as follows, as shown in FIGS. 2, 3, and 4, respectively.

That is, the cutter bit 4 of this embodiment
According to the mounting structure 2 of the above, each cutter bit 4 is provided with a shank 5 made of nickel chrome molybdenum as a vertically long short column member having a parallelogram cross section, and a pair of acute angles facing the shank 5 on opposite sides. And a cemented carbide tip 8 as a cutting tip made of tungsten carbide, each of which is embedded and fixed in a cutting tooth shape. A through-hole 7 through which the wire 6 is inserted is formed.

A pair of locking piece receiving grooves 7a and 7b are formed on the inner peripheral surface of the through hole 7 in the longitudinal direction of the cutter bit 4, and each of the receiving grooves 7a and 7b has A locking piece 9 having a height greater than the depth of a locking groove 6a formed in the rotating shaft 6 described later is urged toward the center of the rotating shaft 6 by the first spring 11 and the second spring 12. Each is accommodated (see FIG. 4).

Further, one of the pair of locking piece receiving grooves 7a, 7b has a third locking piece receiving groove 7a between the first shoulder of the receiving groove 7a and the locking piece 9. The spring 13 is interposed in a tension state to urge the locking piece 9 outward of the rotary shaft 6, and a protruding piece is provided at the end of the first spring 11 opposite to the locking piece 9. The protruding rod 10 is urged by the first spring 12 so that the distal end thereof is in contact with the deepest part of the accommodation groove 7a.

That is, according to the internal structure of the locking piece housing groove 7a, the urging force of the first spring 11 is set to exceed the urging force of the third spring 13, so that the locking piece 9 is accommodated in a state where it is urged toward the center of the rotating shaft 6 by a large urging force of the first spring 11,
As a reaction force, the protruding rod 10 is accommodated in a state of being urged outward from the rotary shaft 6, but one end of the cutter bit 4 referred to in FIG. In this state, the projecting rod 10 projects from the worn end face of the cutter bit 4 to release the urging force of the first spring 11 and the urging force of the third spring 13 to release the locking piece. 9 is drawn out of the rotating shaft 6.

Each of the cutter bits 4 having the above configuration is rotatably supported by a rotating shaft 6 that penetrates the through hole 7 and is attached to the cutter face 1.

That is, the rotary shaft 6 is fixedly installed between both inner side surfaces of a cutter face mounting groove 17 having an arc-shaped cross section formed on the surface of the cutter face 1, and supports the cutter bit 4 firmly. In the center part,
An enlarged diameter portion 16 having a cross-sectional shape that matches the cross-sectional shape of the through hole 7 is provided, and the cutter bit 4 is rotatably supported via a bearing mechanism provided around the enlarged-diameter portion 16. A locking groove 6a is formed on the outer peripheral surface of the enlarged diameter portion 16 of the rotating shaft 6 so as to be fitted and locked with the locking piece 9 at the surface side of the cutter face 1.

Further, according to the mounting structure 2 of the cutter bit 4 of this embodiment, one end is fixed to the rotary shaft 6 and, after being wound around the rotary shaft 6, the other end is shank 5. A pair of coil springs 22 as urging means, which are fixed to the rotary shaft 6, are urged to rotate the shank 5 in the direction of the arrow in FIG. Is provided.

Then, in order to perform tunnel excavation work by using the shield excavator 20 having the cutter face 1 on which the plurality of cutter bits 4 are mounted by the mounting structure 2, the locking piece receiving grooves 7 of each cutter bit 4 are required.
a and 7b are opposed to the surface of the cutter face 1 in a direction perpendicular to the surface of the cutter face 1, and one of the locking piece housing grooves 7 in which the protruding rod 10, the first spring 11, the third spring 13 and the like are housed.
a is positioned on the surface side of the cutter face 1 so that the tip of the locking piece 9 is engaged with the locking groove 6a to fix the cutter bit 4. And
By rotating the cutter face 1 in such a state, the cutting face is cut by one of the carbide tips 8 protruding from the surface of the cutter face 1 (see FIG. 3A).

During such a cutting operation of the face, the carbide tip 8 constituting each cutter bit 4 and the shank 5 surrounding the tip are partially damaged to a considerable extent due to wear or damage. Then, at the end face of the lost cutter bit 4, the leading end of the locking piece receiving groove 7 a is opened, or the end face of the cutter bit 4 is pierced by the biasing force of the first spring 11 to protrude from the end face. Project (see FIG. 3B).

Therefore, when the urging forces of the first spring 11 and the third spring 13 are released, the locking piece 9 is pulled out of the rotary shaft 6 and the engagement with the locking groove 6a is stopped. The cutter bit 4 is automatically released, whereby the cutter bit 4 is automatically rotated along the outer peripheral surface of the enlarged diameter portion 16 of the rotating shaft 6 by the urging force of the coil spring 22.

Further, when the cutter bit 4 which rotates around the enlarged diameter portion 16 as described above rotates by 180 °, the cutter bit 4 moves to a position where the other locking piece receiving groove 7b coincides with the locking groove 6a. At the same time, the locking piece 9 accommodated in the accommodation groove 7b is pushed into the engagement groove 6a by the urging force of the second spring 12 and fitted therein (FIG. 3B). reference).

That is, the cutter bit 4 is 180 °
By being automatically fixed again after the rotation, the carbide tips 8 projecting from the surface of the cutter face 1 and contributing to the cutting operation are automatically replaced, and the cutting operation is subsequently performed. . Therefore, according to this embodiment, a long-distance tunnel excavation operation can be easily performed while automatically and easily replacing the cutter bit 4 that has been worn and the cutting function has been impaired.

In the above embodiment, in order to simplify the construction, the carbide tips 8 are provided at two positions opposite to the cutter bit 4 and two corresponding locking piece receiving grooves are provided. 7a and 7b are provided, and the cutter bit 4 is
Although the description has been given of the case where the cemented carbide tip 8 is rotated and used for replacement, the replacement method of the cutter bit of the present invention is not limited to such an embodiment, and the cutting tip and the locking piece corresponding thereto are Three or more accommodation grooves are provided, and at least two or more engagement piece accommodation grooves have the same configuration as the above-described engagement piece accommodation groove 7a, and each cutting tip is engaged with and fixed to the cutter bit at predetermined angular intervals. They can also be used sequentially.

Further, the method of replacing the cutter bit of the present invention can be adopted without being limited to the one provided with the mounting structure 21 for the cutter bit 4 having the above configuration.

Furthermore, in the above embodiment, the case where the present invention is applied to a cutter bit used as a teeth bit in a muddy shield excavator having a face plate type cutter face 1 has been described. The present invention is not limited to the embodiment, and FIG.
Can be applied to a shield excavator having a spoke type 50 cutter face, a shield excavator having a dome type cutter face, and the like. It can be used in various types of shield machines.
Further, the present invention is not limited to cutter bits used as tooth bits, and can be used for various types of cutter bits such as an outer peripheral bit, a ring bit, and a disc roller bit.

[0034]

As described above in detail, according to the cutter bit replacing method of the present invention, the cutting operation is performed by rotating and locking the cutter bit in accordance with the wear state of the cutter bit. Cutters that can automatically and easily replace the cutting inserts that contribute to the cutting work, without the need for special auxiliary methods or additional work such as the installation of shafts, and the cutter whose function has been impaired due to wear or damage It is possible to easily recover the cutting function of the bit and easily perform a long-distance tunnel excavation operation by the shield machine.

According to the cutter bit mounting structure of the present invention, the fixed state of the cutter bit can be easily released by the biasing force of the elastic member when the one end of the cutter bit is worn by a predetermined amount. After rotating the cutter bit by 180 °, it is possible to automatically and easily perform the work of re-engaging and fixing, so that there is no need for a special auxiliary method or ancillary work such as installation work of a shaft. By replacing a cutting tip that contributes to a cutting operation, the cutting function of a cutter bit whose function has been impaired due to wear or damage can be easily restored.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of a shield machine including a cutter bit mounting structure according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing how a cutter bit is attached to a cutter face.

FIGS. 3A to 3C are cross-sectional views illustrating a situation in which the cutter bit is rotated to replace a worn cutter bit.

FIG. 4 is an enlarged sectional view taken along line AA of FIG.

FIG. 5 is a schematic perspective view showing a situation in which the cutter bit mounting structure of the present invention is applied to a spoke type cutter face.

[Explanation of symbols]

 Reference Signs List 1,50 Cutter face 2 Cutter bit mounting structure 4 Cutter bit 5 Shank 6 Rotating shaft 6a Lock groove 7 Through hole 7a, 7b Lock piece receiving groove 8 Carbide chip (cutting chip) 9 Lock piece 10 Protruding rod ( Projection piece) 11 First spring (elastic member) 12 Second spring (elastic member) 13 Third spring (elastic member) 16 Enlarged portion (rotary shaft) 20 Shield excavator 22 Coil spring (biasing means)

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E21D 9/08

Claims (3)

(57) [Claims] 1. A replacement method for replacing a cutter bit attached to a cutter face of a shield machine when the cutter bit is worn by a cutting operation, the method comprising the steps of: The cutting shank is attached, and the shank is urged to rotate about a central portion thereof, and the shank is engaged at each position where the plurality of cutting tips protrude from the front face of the cutter face. The cutter bit is attached to the cutter face in a state where the cutter bit can be stopped and fixed, and at each position where the cutting tip projects from the front surface, when the cutter bit is considerably worn, the locking and fixing of the shank is released. Then, the shank is rotated by the urging force, and A cutting tip that contributes to the cutting operation by locking and fixing the shank at a position where the tip projects from the front surface of the cutter face, thereby replacing the cutting bit. 2. A pair of said cutting tips are provided at both ends of said shank, and said shank is moved by said biasing force.
2. The method for exchanging a cutter bit according to claim 1, wherein the cutting tip is exchanged and used by rotating and fixing by 0 °. 3. A mounting structure for a cutter bit to be mounted on a cutter face of a shield machine, wherein the cutter bit includes a pair of cutting tips provided at both ends of a shank serving as a base material, and penetrates a central portion of the shank. A rotating shaft that rotatably supports the cutter bit, a locking groove provided on the outer peripheral surface of the rotating shaft on the surface side of the cutter face, and a through hole in a shank central portion through which the rotating shaft passes. On the inner peripheral surface, a pair of locking piece receiving grooves provided to face each other in a direction intersecting with the surface of the cutter face, and an elastic member is provided inside each of the locking piece receiving grooves at the center of the rotating shaft. A locking piece having a height exceeding the depth of the locking groove, which is housed in a state of being urged toward the inside, and at least one of the locking piece housing grooves, By projecting and extending from the locking piece in a state of being urged outward from the rotation shaft via an elastic member, a projecting piece whose tip end is located at the end of the shank, the shank, and the Urging means interposed between a rotating shaft or a cutter face and urging the shank to rotate around the rotating shaft, one of the locking piece receiving grooves having the protruding piece, and The engaging piece and the engaging groove are engaged and fixed in a state where the engaging piece is positioned on the surface side of the cutter face, and the cutting operation of the face face is performed by one of the cutting tips projected and fixed from the surface of the cutter face. At the same time, when the tip of the cutter bit is worn by a predetermined amount, the projecting piece is projected from the end face of the shank by the urging force of the elastic member to release the engagement between the locking piece and the locking groove. And before After the cutter bit is rotated by 180 ° by the urging means, the locking piece housed in the other opposing locking piece housing groove is engaged and fixed to the locking groove by the urging force of the elastic member. Thus, the cutting tip attached to the end opposite to the worn end is fixed so as to protrude from the surface of the cutter face, and the cutting operation is performed by the cutting tip. Construction.